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THE HUMAN BODY. 



each tubule divides several times. At first the branches are 

 smaller than the main tube; but as soon as they have come 

 down to about 0.04 mm. ( v fa inch) this diminution in size 

 ceases, and division continuing while the tubules retain the 

 same diameter, the pyramid thus gets, in part, its conical form. 

 Ultimately each branch runs out of the pyramid somewhere, 

 either from its base or side, into the cortex and there dilates 



FIG. 133. Section through the right Kidney trom its outer to its inner border. 

 I, cortex; 2, medulla: 2', pyramid of Malpiglii; <!", pyramid of Ferreiu; 5, small 

 branches of the renal artery entering between the pyramids: A, a branch of the 

 renal artery; Z>, the pelvis of the kidney; U, ureter; C, a calyx. 



and is twisted. It then narrows and doubles back into one of 

 the pyramids of Ferrein and runs as a straight tube towards 

 the papilla, but before reaching it makes a loop (loop of Henle], 

 and turns back again as a straight tube towards the base of 

 the pyramid, where it once more enters the cortex, dilates 

 and becomes contorted, and then ends in a spherical capsule, 



